The original goals of the RPEU were to 1) develop a state-of-the- art recombinant protein expression facility to fill the gap between gene isolation and protein function/structure and 2) provide or assist in the production of milligram-to-gram amounts of adequately folded and post-translationally modified near clinical-grade material for preclinical studies of promising parasite vaccines. With the development of a NIAID Malaria Vaccine Initiative, the goals have been expanded to include a broader scope of activities required to assure the timely production and testing of malaria vaccines?the new unit is called the Malaria Vaccine Development Unit to reflect those expanded responsibilities. The MVDU will consist of five teams: 1) an Expression/Production Team for designing and engineering recombinant DNA for transfection into bacteria, yeast, baculovirus and mammalian cells and production and optimization of fermentation/growth conditions; 2) a Product Recovery Team that works on post-production process development and does preliminary analysis of the resultant recombinant protein for structural and immunological integrity; 3) a Process Support Team that controls the raw materials, intermediates and final product analysis, the immunogenicity and formulation issues that arise and oversees the contracts required for outsourcing product development; 4) a Quality Control/Assurance Team that assist in meeting the regulatory requirements for production of clinical- grade material; and 5) a Clinical Testing Team that conducts or assists in the clinical testing of MVDU-derived products. Currently, a large effort is being put into the design and construction of a Process Development/Production facility capable of performing the process development, the detailed Good Manufacturing Practice-grade documentation to support the transfer of technology to GMP pilot plants and the actual production of small lots of clinical-grade material in controlled environments required for human Phase I and II trials. The MVDU interacts with a number of large number collaborators including LPD and extramural scientists whose major goals are studying the functional/immunological and structural characteristics of recombinant parasite proteins. The MVDU has provided substantial amounts of materials and resources required to establish the new NIAID Malaria Reagent Repository. Current projects in the MVDU include 1) pre-erythrocytic malaria parasite antigens expressed in yeast (CSP and TRAP); 2) recombinant asexual blood stage antigens expressed in bacteria, yeast, baculovirus, mammalian cells and transgenic animals (MSP1, MSP3, MSP4, MSP5, AMA1, SERA, PfEMP1, RAP2); 3) preparation of the Master and Production Cell Bank for GMP production of a malaria asexual blood-stage antigen (P30P2MSP1-19) and optimization of production of proteins (TBV25H and P30P2MSP1-19) in yeast; 4) Pvs25 and Pvs28, Pys25 and Pys28, Pbs21, Pgs25 and Pgs28 for the study of P. vivax, P. yoelii, P. berghei, P. gallinaceum, respectively, ookinete invasion of mosquito midguts, and An. gambiae late midgut trypsin; 5) schistosomiasis antigens (Calpain and Paramyosin); 6) onchocerciasis antigens (OV 11.21 and aldolase); and 7) Leishmania antigens (3'-nucleotidase and chitinase). We have started to explore the utility of recombinant Leptomonas as an expression system for heterologous protozoan protein expression. The MVDU has capabilities at 1, 5 and 10 Liter scale and now has a Class 100 clean room for preparation of ultra-pure, endotoxin- free recombinant protein for preclinical studies. The RPEU supplied the documentation for production of clinical-grade P30P2-MSP1 and TBV25-28 and was the lead agency filing a FDA- approved IND application for testing P30P2-MSP1 in a Phase I human clinical trial. Plans are in development for coordinating the infrastructure necessary for timely production and clinical testing of malaria vaccines (asexual blood stage and transmission-blocking).